The second model is designed for black powder cartridges, but the gun will tolerate some use with modern ammo - it may eventually stretch or get a bit loose, but won't "explode" or anything.
They are very well designed, have rebounding hammers very similar to the Ruger revolver design, but made in the 1880's - I have a 2nd model in .38 S&W made in 1889, and I really like it a lot.
FWIW, the .32 S&W is rated around 90 ft/lbs., more than the .25 auto pistol cartridge. It was a real competitor with the early .25's, and a lot of these small revolvers were sold because they were more reliable and a bit more powerful ( with more penetration) than the autos.
Many working and business people bought and used them for personal protection from the 1880's till WWII, and I think they are very interesting because of that.
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